Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands |
1 Months Ended | 3 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|---|
Jul. 20, 2018 |
Jul. 31, 2018 |
Feb. 28, 2018 |
Sep. 30, 2018 |
Sep. 30, 2018 |
Sep. 30, 2019 |
Dec. 31, 2018 |
|
| Convertible Preferred Stock | |||||||
| Proceeds from issuance of convertible preferred stock | $ 100,986 | ||||||
| Payments of initial public offering costs | $ 3,449 | ||||||
| Preferred stock outstanding | 0 | 0 | |||||
| Series C convertible preferred stock | |||||||
| Convertible Preferred Stock | |||||||
| Preferred stock issued | 7,912,432 | ||||||
| Convertible preferred stock issue price (dollars per share) | $ 12.79 | ||||||
| Proceeds from issuance of convertible preferred stock | $ 101,200 | ||||||
| Payments of initial public offering costs | $ 200 | ||||||
| Common stock | |||||||
| Convertible Preferred Stock | |||||||
| Number of common stock issued on conversion | 51,845,438 | 51,845,438 | 51,845,438 | ||||